Funny you'd mention it; I write summaries of most non-fiction books I read and Atomic Habits stood out in particular in that its summary runs only about a single page. I reproduce it here, though you may want to copy it into something that can render markdown. (On a side note, I every so often mourn the fact that there seems to be no market for concise books. I think the publishers are right about this, padding really does increase their profit and makes it easier to justify the price of a book to the average buyer. Still, many books would just be way better books if they were one fifth as long.):

# Identity

There are only two possible foundations for long-term behavioural change:
1. a re-prioritisation of personal values
2. a substitution of an existing behavior $X$, which is based on a personal value $V$, with a different behavior $Y$, which is also based on $V$.

# Dealing with Existing Habits

Before we can effectively build new habits, we need to get a handle on our current ones. All habits serve you in some way—even the bad ones—which is why you repeat them.

# Implementation Intentions

Implementation intentions (https://en.wikipedia.org/wiki/Implementation_intention) have been empirically shown to be effective. The idea behind implementation intentions is to eliminate ambiguity. Explicitly write down WHEN and WHERE you will do WHAT.

Write down a list of implementation intentions for all habits you wish to develop.

# Three Layers of Behavior Change

1. Identity
2. Process
3. Outcome

Identity is what you believe, process is what you do, outcome is what you get.
Systems lead to outcomes.

# Four Steps of Habit Formation

1. Cue (triggers behavior)
2. Craving (desired change of state)
3. Response (behavior performed to achieve change of state)
4. Reward (outcome delivered by response)

Of these four, only cues can reliably be manipulated. Design your environment around the habits you wish to develop. The two most common cues are time and location.

## Breaking Habits

1. Remove the cues from the environment.
2. Expose how the bad habit inadequately addresses the underlying motive that caused its formation. Clearly describe the negative consequences of the habit in writing.
3. Replace the bad habit with a good one that more effectively addresses the underlying motive.

# Habit Scorecard

You need to be aware of your habits before you can change them. To create your scorecard, write down everything you do for an entire day. At the end of the day, mark each behavior as either bad, neutral, or good.

# Underlying Motives

* *Reducing uncertainty*
* Conserve energy
* Social bonding
* Social approval

Cravings are arbitrary manifestations of underlying motives. Evolution hasn't set up our brain to reward e.g. playing video games in particular. But it did set up our brain to reward a reduction in uncertainty.
Products and services don't create fundamentally new motives, they latch on to existing ones.

# Miscellaneous

Without good health habits, you will always seem to be short on energy.

It is easier to associate a new habit with a new context, than to build a new habit in the face of competing cues.

You can break a habit, but you’re unlikely to forget it. This means that trying to resist temptation is an ineffective strategy. In the short-run, you can choose to overpower temptation. In the long-run, environmental cues overpower you.

Every day has multiple decisive moments, where split-second decisions decide how you will spend the next one to three hours. It's easier to continue what you are doing than to start it.

In deliberate thoughts, as well as in speech, always use formulations of the form "I go for a run", not "I have to go for a run", regardless of how you feel about it.

Every habit is about overcoming obstacles to get what you want. You don't want the habit itself, you want what it delivers.